For an electrical engineer, it is a basic circuit design effort. But even if the circuit schematics and then perfect, if the PCB board into the process, not the common problems and challenges understanding and prevention, the entire system can still be compromised, serious when can not work. In order to avoid changing the engineering design, improve efficiency, reduce costs, so today I will place the most prone to problems one by one explanation.
First, component selection and layout
specifications of each component is different, even if the same element characteristics of products made by different manufacturers may not be the same, so the choice in the design of components, it is necessary to contact in order to understand the characteristics and components supplier and know the impact of these characteristics on design.
In today, choose the right memory is a very important thing for electronic product design, the result of constant updating DRAM and Flash memory, PCB designers want a new design is not affected by the changing external market for its memory It is a big challenge. DDR3 is now occupied by the current 85% -90% DRAM market, but DDR4 is expected to rise from 12% to 56% in 2014. So designers must aim tight memory market, maintain close contact with the manufacturer.
Component overheating
further large amount of heat for some components must perform the necessary calculations, the layout they require special consideration, a large number of components together can generate more heat, causing deformation of the solder resist layer was separated, and even ignite the entire board. Therefore, the design and layout engineers must work together to ensure that there are appropriate layout elements.
When the layout of the first to consider the size of PCB. When the PCB size is too large, the printing line length, the impedance to increase, decrease noise immunity, the cost increases; too small, the heat is not good, and adjacent lines susceptible to interference. After determining the size of the PCB, and then determine the position of the particular element. Finally, the functional units of the circuit, all the components of the circuit layout.
Two cooling system
designed cooling system includes a cooling method and cooling components selection, and consideration of cold expansion coefficient. There are currently employed by the PCB heat dissipation PCB board itself, plus the heat sink and the heat plate.
Conventional PCB design, since the multiple use of a copper-clad sheet / glass cloth base material epoxy or phenolic resin glass cloth base material, and a small amount of paper-based CCL material used, these materials are good electrical properties and processability, but the thermal conductivity very poor. Now that the design of QFP, BGA and other surface mounted components use a large amount, a large amount of heat generated by the components of the PCB to pass, so that the best way is to increase the heat dissipation capability of the PCB itself in direct contact with the heating element, by PCB board conducted away or dissipated.
When the PCB heat than a few large devices, may be added to the heat-generating device or a heat sink in heat transfer tube, when the temperature is not down, may be employed with the radiator fan. When a large amount of heating devices, can be a large heat shield, the heat shield element on the entire surface of the fastener, and each member in contact with the heat dissipation. For a professional video and computer animation, and even require water-cooled way cool.